/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.extensions.sql.impl.udf;



import java.lang.reflect.Method;

import java.util.Arrays;

import java.util.List;

import java.util.Map;

import java.util.stream.Collectors;



/** UnifiedBuiltinFunctionClass interface. */

public abstract class UnifiedBuiltinFunctionProvider {

  public Map<String, List<Method>> getBuiltinMethods() {

    List<Method> methods = Arrays.asList(getClass().getMethods());

    return methods.stream()

        .filter(UnifiedBuiltinFunctionProvider::isUDF)

        .collect(

            Collectors.groupingBy(method -> method.getDeclaredAnnotation(UDF.class).funcName()));

  }



  private static boolean isUDF(Method m) {

    return m.getDeclaredAnnotation(UDF.class) != null;

  }

}